..The results of this study suggest that in iguana, a negative feedback loop involving dopamine and melatonin regulates the circadian rhythm of the ERG b-wave amplitude that is at least in part generated in the brain...

..Aging seems to affect rhythms in some but not in all tissues and may act primarily on interactions among circadian oscillators, perhaps attenuating the ability of the SCN to drive damped oscillators in the periphery...

..The data suggest that in iguanas, the amplitude of the circadian rhythm of melatonin synthesis in the eye is suppressed by dopamine while the rhythm of dopamine depends, at least in part, on the presence of melatonin...

..These data, together with many others in the literature, point to a complicated interaction between the circadian system and the development and possible treatment of psychopathologies such as bipolar disorder and drug addiction...

..The responses at the highest irradiances were significantly greater in species occupying relatively more shaded habitats, suggesting that non-visual photoreception may be adapted to habitat light in Anolis lizards...

..The presence of an intact retina appears to contribute to system-level circadian organization in mammals perhaps as a consequence of interaction between its circadian oscillators and those in the SCN...

Circadian rhythmicity in dopamine content of mammalian retina: role of the photoreceptors

..Our results demonstrate for the first time clear circadian rhythms of dopamine content and turnover in a free-running mammal, and suggest that rods and cones are not required for dopamine rhythmicity...

Effects of circadian regulation and rest-activity state on spontaneous seizures in a rat model of limbic epilepsy

..Control injections of saline solution had no effect. The significance of these results is discussed in relation to the role of the pineal complex and melatonin in the mediation of thermoregulatory behavior...

The tau mutation shortens the period of rhythmic photoreceptor outer segment disk shedding in the hamster

..These results strongly suggest that endogenous melatonin, released by the pineal gland and the retinae, regulates the timing of feeding rhythms by entraining other oscillators in the circadian system of the pigeon...

The clock in the mouse retina: melatonin synthesis and photoreceptor degeneration

..We hypothesize that the ovarian circadian clock is entrained by hormonal signals from the pituitary and that ovulation depends, in part, on the phase in the ovarian circadian cycle at which these signals occur...

..In this paper, we review evidence for clock function in the ovary across a number of species and offer a novel perspective into the role of this clock in normal ovarian physiology and in diseases that negatively affect fertility...

Social stimuli fail to act as entraining agents of circadian rhythms in the golden hamster

..A substantial number of clinical studies indicate associations between sleep abnormalities and drug abuse; however, the role played by the circadian system in the development of addiction is largely unknown...

..These results demonstrate that peripheral tissues express self-sustained, rather than damped, circadian oscillations and suggest the existence of organ-specific synchronizers of circadian rhythms at the cell and tissue level...

..75-kb mPer1 promoter fragment is sufficient to confer both circadian and photic regulation in vivo and reveals a potential posttranscriptional regulatory mechanism within the mammalian circadian oscillator...

Period and phase control in a multioscillatory circadian system (Iguana iguana)

Research Grants1

..Furthermore, it is basic to the design of treatments for many serious conditions (e.g., high blood pressure, cancer) in which responses to therapeutic agents are modulated both positively and negatively by the circadian system. ..